Scancell welcomes new study in The Journal of Clinical Investigation

14th March 2013

Scancell Holdings Plc, (AIM:SCLP), the developer of therapeutic cancer vaccines, would like to alert shareholders to the recent article “IgG4 subclass antibodies impair antitumor immunity in melanoma” in the peer reviewed cancer journal: The Journal of Clinical Investigation, published on 1 March 2013.

The new study published in The Journal of Clinical Investigation supports earlier studies by King’s College London that indicate that patients with the cancer, malignant melanoma, appear to elicit a weak antibody response to the tumour cells which appears to be relatively ineffective in combating the cancer and which may in effect switch off the immune system.

This study indicates that patients with malignant melanoma initiate a B cell immune response to produce an antibody called IgG4. IgG4 is considered a “weak” subclass of antibody and is thought to inhibit the production of other stronger antibodies such as IgG1, actually protecting the tumour cells from a more effective and aggressive attack from the patients’ immune system.

Scancell’s melanoma cancer vaccine SCIB1, which is currently in Part 2 of a Phase I/II clinical trial, works by activating the immune system through T cells rather than B cells. The Board believes that T cell activation is a more effective approach to treating patients with an immune system compromised in the manner found in those with malignant melanoma.

Dr Richard Goodfellow, joint Chief Executive Officer of Scancell, comments: “We believe that The Journal of Clinical Investigation paper supports Scancell’s approach to fighting cancers, such as malignant melanoma, where T cell activation appears to be the more effective route of combating this often fatal disease. Results from our Phase I/II clinical trial are expected at the end of this year.”

Scancell is developing therapeutic vaccines for the treatment of cancer and infectious diseases based on its ImmunoBody® and Moditope™ technology platforms. Scancell’s first cancer vaccine SCIB1 is being developed for the treatment of melanoma and is in Phase 1/2 clinical trials. Preliminary evidence from Part 1 of the study showing that SCIB1 produced an immune response which might be associated with clinical benefit in patients with malignant melanoma was released in December 2012.

Treating cancer by vaccination allows small non-toxic doses of a vaccine to be administered to a patient, stimulating an immune response. Effective cancer vaccines need to target dendritic cells to stimulate both parts of the cellular immune system; the helper cell system where inflammation is stimulated at the tumour site; and the cytotoxic T-lymphocyte or CTL response where immune system cells are primed to recognise and kill specific cells.

A limitation of many cancer vaccines currently in development is that they cannot specifically target dendritic cells in vivo. Several groups have demonstrated successful vaccination by growing dendritic cells ex vivo, pulsing them with tumour antigens and re-infusing them. However, this procedure is patient specific, time consuming and expensive. Scancell has developed its breakthrough patent protected ImmunoBody® technology to overcome these limitations.

Scancell has also identified and patented a series of modified epitopes that stimulate the production of killer CD4 that destroy tumours without toxicity. The Directors believe that the Moditope™ platform could have a profound effect on the way that cancer vaccines are developed.